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9- m 8 h S P e 8 h S 2 D L E .I I N E E R G T H no. Modem UNDERGROUND CONDUIT.

No. 570,168. Patented Oct. 27,1896.

WITNESSES ATTORNEY n: wnms Psrsns C0,. mom-imam wAsMNGTcN. n. c.

NITED STATES PATENT FFICE.

EDIVIN T. GREENFIELD, OF NEIV YORK, N. Y., ASSIGNOR TO THE INTERIOR CONDUIT AND INSULATION COMPANY, OF SAME PLACE.

UNDERGROUND CONDUIT.

SPECIFICATION forming part Of Letters Patent N0. 570,168, dated October 27, 1896.

Application filed May 11, 1896. Serial No. 591,090. (No model.)

To ctZZ whom, it may concern: sents a wooden trough, preferably creosoted Be it known that I, EDWIN T. GREENFIELD, or treated in any of the well-known ways to a citizen of the United States, residing at protect it from the action of water, and D New York, in the county of New York and a wooden cover therefor. 5 5 State of New York, have made a new and P P P are rows or tiers of subway or conuseful Improvement in Conduits, of which duit tubes made, preferably, of paper treated the following is a specification. or cured in the usual way with insulating My invention is directed to improvements material, said tubes being properly spaced in electrical conduits, but particularly unand sustained by wooden spacing-strips when 60 1o dergro'und or subway conduits; and its obthey are laid in the conduit-trough D and jects are, first, to afford a simple and efliafterward surrounded with molten asphalt or cient means for insulating electrical conducpitch, which is allowed to harden, after which tors at manhole-crossings in systems of subthe cover D is secured in place. ways or underground conduits; second, to M represents the top or upper portion of a 65 construct a manhole in sectional parts, so as manhole, made, preferably, of cast-iron and to adapt the same for any desired number of of rectangular form, said top portion being subway or conduit tubes; third, to afford strengthened by radially-disposed ribs It R generalflexibility of interconnection between &c., and T is a removable cover therefor. the ends of subway or conduit tubes as they The lower surface of this top portion of the 70 enter a manhole or point of distribution by manhole is provided with a rim, flange, or the use of flexible insulating or protecting extension K, which is adapted to fit snugly tubes. I accomplish these several objects over the rectangular portionO of the body of with the means hereinafter described, the esthe manhole, which rectangular portion is pecial features of. novelty of my invention provided with a similar flange at its lower 75 being particularly pointed out in the claims surface adapted to fit in a like manner over a at the end of this specification. corresponding flange upon another sectional Referring now to the drawings, Figure 1 part 0. The bottom sides of the top portion represents in part sectional and part side-ele- M and the corresponding top and bottom vational view a subway or conduit embracing sides of the portion 0 are provided with semi- 8o 0 two tiers of subway or conduit tubes and my circular openings F F, which, when the parts improved form of manhole, with a flexible are placed one upon-the other, after the manprotecting-tubing joining one of said conner shown in Fig. 3, constitute the inlets for duit-tubes to a branch leader or circuit 10- the conduit or subway tubes P P. By thus cated above ground. Fig. 2 represents in constructing the manhole of sectional parts 8 5 3 5 plan view a subway or conduit embracing a O O, I am enabled to build up a manhole to number of subway or conduit tubes entering any desired height, so as to accommodate a manhole and provided with my improved any number of subway or conduit tubes, this means of effecting flexible interconnecting feature of flexibility of a manhole being protecting means for uniting any pair of such deemed by me as important, in that it adapts 9o 40 subway 0r conduit tubes, the top of the manthe invention for ready use in accordance hole and the cover of the subway being rewith the demands of the system where used. moved for the purpose of illustrating the in- The lower or bottom section of the manhole terior structure of said parts. Fig. 3 is a O is provided with an outlet J for drainage. transverse section taken on the line a; a, Fig. In the top portion of the manhole I provide 5 5 1, and as seen looking from right to left in an opening through a projecting portion L the direction of the arrows upon that figure for the purpose of enabling one to convey a of the drawings. Fig. 4c is a plan view of the branch feeder or main from the subway to a manhole as seen looking at Fig. 3 from the point above ground, as an electric light post top toward the bottom of the drawings. or any other service usage. WVhen' the man- ICO Referring now to the drawings in detail, hole is placed in position between the adjaand first to Figs. 1 to 4, inclusive, D reprecent ends of the subway, so that the openings F F are in alinement with the incoming subway or conduit tubes 1 l I I as shown in Figs. 1 and 2, I insert short metallic sleeves I 1 through the openings F F and around the incoming subway or conduit tubes, said sleeves being provided with screw-threads on their inner ends. I then provide a temporary dam around said screw-threaded sleeves at the openings and pour liquid asphalt in the conduit-box I) around the free ends of the pipes I and the adjacent ends of the metallic sleeves P until the spaces around the tubes and sleeves are completely filled with said asphalt, thereby making an absolutely water-tight joint between the manhole, the conduit-boxes, and the contained tubes and sleeves.

It R R represent expansible soft-rubber tubing of sufficient length, when expanded, to afford cross connection between any pair of subway or conduit tubes located within the manhole. These tubes R R are secured by wire wrappings u: an at their opposite ends to T-shaped hard-rubber thimbles t t.

N N are swivel locking-nuts screw-threaded on their inner surfaces and each provided with a shoulder having a bearing against the T-shaped portion of its thimblc 2, as clearly shown in Figs. 1 and 2.

\Vhen it is desired to cross-connect any pair of subway or conduit tubes P P, the conductor is drawn therethrough to the manhole and one of the flexible interconnecting tubes R R is secured to the inner end of said subway-tube in the manner shown in folded position near the center of Fig. 2. The conductor is drawn forward to the other conduittube through which it is to be conveyed and the swivel-nut N is connected to the screwthread upon the sleeve which surrounds said subway tube or conduit, thereby expanding the soft-rubber tube in the manner shown in the bottom portion of the drawings in Fig. 2.

In Figs. 1 and 3 I have illustrated a means of connecting one of the subway-tubes with a lamp-post or other point of service aboveground and surrounding the conductor running thereto by one of my improved flexible insulating-tubes, R representing such tube and being provided at its opposite ends with insulating-thimbles z. t and locking-nuts I\", one of which is secured to the upper portion of a locking-thimble K, provided with insulatinglinings 1 I, the outer end of said flexible tubing being connected by the swivelnut X to the end of a tube which is secured to the manhole by two nuts Q Q, as clearly shown in Fig. 3. \Vith such an arrangement of flexible tubing I am enabled to furnish cross connections between any two of a se ries of subway-tubes and to afford quick and easy access to the conductor or conductors surrounded thereby. I am also enabled to in a similar manner insulate with one of my improved flexible eross-connectors any conductor which runs to a point aboveground.

I am aware that it is broadly old to crossconnect subway-tubes in manholes by rigid telescoping sleeves, and I make no claim hereinafter broad enough to include such a structure, my broadest claim in relation to such cross connections being the feature of flexible cross-connecting tubes which permit of any interconnection desired.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is- I 1. In a subway or conduit a series of con duit-tubes extending into a manhole or to a point of distribution, each of said conduittubes being provided with screw-threaded ends and corresponding screw-tl'ireadcd locl ingnuts attached to short sections of insulating-tubing for cross-connecting said tubes, substantially as described.

2. In a subway or conduit a series of conduit-tubes extending into a manhole or to a point of distribution, in combination with expansible cross-connecting tubes and means for securin g said expansible tubes to any pair of said cond nit-tubes, whereby the insulating continuity of said tubes is effected substantially as described.

3. A pair of conduit-tubes having their ends located in close proximity to each other, in combination with an expansible insulating connecting-tube provided with means for uniting the opposite ends thereof to said eonduit-tubes, substantially as described.

In a subway or conduit a series of cond nit-tubes extending into a manhole from opposite sides, in combination with a series of expansible cross-connecting tubes provided with means for connecting said expansible tubes to the ends of the oppositely-located conduit-tubes, substantially as described.

5. A subway or conduit provided with expansible means for joining two or more con duit-tubes and an expansible side or branch tube running therefrom to a service conduittube located aboveground, substantially as described.

(3. In a subway a series of conduit-tubes extending into a manhole, in combination with a series of expansible cross-connecting tubes adapted to connect said conduit-tubes together in pairs and expansible branch connecting-tubes, one or more, for connecting said conduit-tubes to lateral or side branches, substantially as described.

7. In a subway system a series of conduittubes extending into a manhole; a series of expansible cross-connecting tubes for crossconnecting said conduit-tubes together in pairs, in combination with detachable means for securing said cross-connecting tubes to the ends of the tubes, substantially as de- .seribed.

8. A subway consisting of a series of conduit-tubes located in a conduit-tube trough, the ends of said tubes extending into a manhole and being surrounded each by a short metallic sleeve and all embedded in asphalt which binds the tubes, the sleeves, the consectional parts provided each with a rim,

flange or extension and semicircular openings in the opposite edges of the parts, the arrangement being such that when the separate sections of said manhole are placed the one upon the other the opposite semicircular parts constitute openings for the admission of conduit-tubes, substantially as described.

In testimony whereof I have hereunto subscribed my name this 8th day of May, 1896.

EDVIN T. GREENFIELD.

lVitnesses: O. J. KINTNER, (J. HAKEMEYER. 

